Thousands of well-wishers from across Britain turned out alongside senior members of the royal family yesterday to see a rejuvenated and healthy Queen Mother celebrate her 101st birthday.

Unbowed by her recent health scare, and visibly buoyed after last Wednesday's blood transfusion for anaemia, she stepped out of the gates of her London home, Clarence House, to receive gifts from children. 'I'm feeling much better,' she told well-wishers.

The Queen Mother, dressed in pale turquoise, was on her feet for nearly 15 minutes as she took the salute of the Scots Guards, marching past with the Band of the Grenadier Guards playing 'Happy Birthday'. Only for a brief moment did she seem to lose her balance, laying down her two walking sticks to sit on a chair strategically placed behind her as she took the salute.

'Doesn't she look great?' said Neil Harris, 45, who was down with his family from Newcastle. 'You'd never think that she'd had a scare: I mean, look at how colourful she looks. I'm really glad I'm here - she is an institution, isn't she? Bless her.'

His wife, Anne, said: 'We were wanting to come to London for the weekend anyway. Then after hearing about her health, we decided to spend the day here - I'm glad we did it. I don't mean to be cheeky, but what are the chances that she'll make it to 102?'

Charles Murphy said: 'It's a shame that not more people are here. I came down from Birmingham yesterday, and to be honest, I thought there'd be a bigger turnout. I mean, she's had a health scare, hasn't she? But I suppose - with the nice weather and all that - people have gone out for the day.'

After almost 45 minutes, the Queen Mother returned though the gates of her London residence, chauffeur driven in her golf cart. She later made a second appearance at the gates, this time with her grandson, the Prince of Wales. Appearing to have no ill-effects from falling off his polo pony on Friday, Prince Charles beamed at the well-wishers. Standing close by were his sons, Princes William, 19, and Harry, 16.

However, there were concerns for another member of the family. Princess Margaret appeared in a wheelchair looking frail and unwell following a series of strokes. In an increasingly rare public appearance, the Queen's sister wore heavy, dark glasses and her left arm was in a sling. Palace officials have refused to confirm whether the Princess's last stroke left her suffering long-term loss of sight or paralysed on one side of her body.

The royals watched as the King's Troop, the Royal Horse Artillery, rode past having earlier fired a 41-gun salute in nearby Hyde Park. 'It's a wonderful way to mark her birthday,' commented Pamela Scott from London. 'All those big guns - it really makes you feel like you've witnessed something special.'

Souvenir sellers reported steady sales throughout the morning. Vicky Cooper, selling flags near the exit of Green Park station, said: 'It's been a brisk trade. I'm selling the wee ones for two quid. And the larger ones go for a fiver. I've had to go into the van and stock up twice already. At this rate, I should be able to shift the lot tonight.'

Shortly afterwards, the Queen arrived from Buckingham Palace for her mother's birthday lunch. Also present were the Duke of York, Princess Beatrice, who is 13 on Wednesday, Princess Eugenie, 11, and the Princess Royal, with her husband Commander Timothy Laurence.

'It's a nice way to spend the morning,' said Tim Cullen, holding a bouquet of flowers. 'And it's nice to see so many of the royals have turned out in force for her. She's had a hard time recently: and I think she'll appreciate all the attention she's getting.'

His son, Andrew, 15, added: 'This is my first time here - and it's good fun. We've had to wait for a bit, though.' The Queen Mother disappeared back into Clarence House for the lunch in the early afternoon, waving goodbye to the crowd, reportedly 7,000 strong.

Last night she and her daughters went to see the Royal Ballet's The Dream and A Month in the Country at the Royal Opera House in Covent Garden.